At this point it is recommended that you replace the circuit board, as this is the most likely cause of the problem. Follow the Nortel Networks i2004 IP Circuit Board Guide and put the new circuit board in instead of the old one.

There may be dust or other particles preventing the buttons from making the circuit they need to provide input. Use the Nortel Networks i2004 IP Buttons Guide to get to the buttons and clean the dust out from the buttons.

Check to make sure that the buttons are not simply misaligned. If they are, attempt to jiggle them back into place. If this does not appear to work, the buttons may be broken. Refer to this guide for help with replacing the Nortel Networks i2004 IP Buttons Guide.